...W. A. Robertson Abstract Thermal and alternating field studies of the remanent magnetization of the Mamainse Point lavas, on the east shore of Lake Superior, indicate stable magnetization. The flows form two groups of normally magnetized (N) flows, each overlying reversely magnetized (R) flows...

...Jonathan H. Berg; Kenneth W. Klewin Abstract Detailed study of the basal 500 m of the Keweenawan Mamainse Point volcanics in Ontario, Canada, has revealed that the section is dominated by basaltic to picritic lavas with up to 23 wt% MgO. Two stratigraphic suites with distinct chemical...

... just north of the well-studied, contemporaneous Mamainse Point Formation. Detailed chemostratigraphy of the Alona Bay lavas suggests they are grossly correlative with the basal portion of the Mamainse Point Formation. For instance, like the basal part of Mamainse Point Formation, the Alona Bay section...

... to this stage. No age dates are available to accurately constrain the start of volcanism, but the lowermost reversed-polarity picritic lavas of the Mamainse Point Volcanic Group and the more Mg rich lavas of the Osler Volcanic Group have been considered to be eruptive equivalents of the ultramafic intrusions...

...Kenneth W. Klewin; Jonathan H. Berg Abstract The Keweenawan (1100 Ma) Mamainse Point volcanics, located along the eastern shore of Lake Superior in Ontario, formed in the Midcontinent Rift of North America. They are a 5250 m thick sequence of over 350 predominantly basaltic lava flows. The Mamainse...

...Jeremy P. Richards; Edward T. C. Spooner Abstract Locally rich (up to 40% Cu) Cu-(Fe) sulfide mineralization with minor Ag occurs in fault-related fissure veins cutting, but probably penecontemporaneous with, Keweenawan plateau basalt lava flows at Mamainse Point, Ontario. Paragenetic studies...

... this stage is a feature of the entire >2500-km-long rift. The succession of picritic and basaltic lava flows at Mamainse Point in the eastern Lake Superior Basin may be the most continuous and best exposed record of rift-related volcanism and magnetic reversals, but its age and duration relative...

... Bay, the lower 6000 ft (1829 m) of North Shore volcanics, the lower 1000 ft (305 m) of Cape Gargantua volcanics and the lower 3000 ft (914 m) at Mamainse Point are of reverse polarity. Normal directions of magnetization, which differ from the reverse directions of magnetization by amounts ranging from...

...N. W. D. Massey Abstract Transitional basalt suites have been recognised in Keweenawan lava sequences at Mamainse Point and Shesheeb Bay, Ontario. These are similar to their accompanying tholeiites in major element chemistry, but have higher, more alkalic contents of incompatible elements...

...N. W. D. Massey Abstract The three reversals in the palaeomagnetic stratigraphy at Mamainse Point have previously been explained by strike faulting causing repetition of a single reversal. There is, however, no geological evidence in support of this faulting, and geochemical data on the lavas...

... Midcontinent Rift lavas were from the lavas exposed at Alona Bay which is 13 km north of Mamainse Point in eastern Lake Superior ( Fig. 1 ; Dubois, 1962 ). These lavas are nearby, and correspond to, the lower reversed polarity zone in the Mamainse Point stratigraphy ( Palmer, 1970 ). This polarity zone...

... : Minnesota Geological Survey, University of Minnesota Digital Conservancy , http://hdl.handle.net/11299/101466 . Klewin , K.W. , and Berg , J.H. , 1991 , Petrology of the Keweenawan Mamainse Point lavas, Ontario; petrogenesis and continental rift evolution : Journal of Geophysical Research...

...) that are parental to intrusions such as those that host the Eagle intrusion ( Table 1 ), and are found in lava successions such as those of Mamainse Point ( Berg and Klewin, 1988 ; Shirey et al., 1994 ), must represent relatively high degree partial melts of the mantle (e.g., Campell, 2007; Herzberg et al., 2007...

..., and platinum group element sulfide mineralization . Economic Geology , 110 : 1235 – 1267 . doi: 10.2113/econgeo.110.5.1235 . Klewin , K.W. , and Berg , J.H. 1991 . Petrology of the Keweenawan Mamainse Point lavas, Ontario: petrogenesis and continental rift evolution . Journal...

... Project , 1981 , Basaltic volcanism on the terrestrial planets : New York , Pergamon Press, Inc. , 1286 p. Berg , J. H. , and Klewin , K. W. , 1988 , High-MgO lavas from the Keweenawan midcontinent rift near Mamainse Point, Ontario : Geology , v. 16 , p. 1003 – 1006...

... . Geochemistry of the Mamainse Point volcanics, Ontario, and implications for the Keweenawan paleomagnetic record . Canadian Journal of Earth Sciences , 27 ( 9 ): 1194 – 1199 . Klewin K.W. Berg J.H. 1991 . Petrology of Keweenawan Mamainse Point lavas, Ontario: petrogenesis and continental...

... Superior Basin . Geological Society of America, Memoir 156, pp.  27 – 45 . Klewin K.W. Berg J.H. 1991 . Petrology of the Keweenawan Mamainse Point lavas, Ontario: Petrogenesis and continental rift evolution . Journal of Geophysical Research , 96 : 457 – 474 . Klewin K.W...